Blowtorch



F. L. SCHWEITZER BLOWTORCH Jan. 30, 195 l 2 Sheets-Sheet 1 Filed Sept. 25, 1946 "n A ...A

l?! i anni.

INVENTOR. /52/7'2 .4. 5mn/#25,?

Jan. 30, 1951 F. l.. scHwElTzER 2,539,595

BLOWTORCH Filed Sept. 25, 1946 2 Sheets-Sheet 2 BY 751W, 85%@ Patented Jan. 30, 1.951

UNITED STATES PATENT OFFICE Claims.

This invention relates to a blowtorch of the type wherein fuel feeding is effected by thermal vaporization of the fuel in the tank as distinguished from that type of torch utilizing pressure pump fuel feeding.

The main object of the invention is to provide a blowtorch of the type specified which is so constructed that it possesses the following advantages:

l. It is more eicient in operation than the prior torches;

2. There is a minimum loss of vaporizing heat due to radiation;

3. The torch maintains its efficiency of operation at all times, even when used out of doors in cold windy weather, even in sub-zero temperatures;

4. Complete vaporization of the fuel occurs thus increasing torch efficiency, causing maximum heat to be produced at the flame nozzle, and requiring a minimum amount of fuel in its operation;

5. The torch comprises a relatively few number of parts and eliminates certain parts now required in the torches of the prior art, thereby reducing the amount of material required in the torch construction, cutting to a minimum the machining and manufacturing operations involved in its production and enabling it to be produced by simple manufacturing operations, many of which are merely stamping operations.

A further and more specific object is to provide a blowtorch construction of the type specied and wherein the heat generated by the flame nozzle is substantially directly transmitted to the fuel in the tank as distinguished from being transmitted thereto by a relatively long conductive path as in the torches of the prior art.

Further and additional objects and advantages not hereinbefore specified will become apparent hereinafter in the detailed description of embodiments of the invention which is to follow.

Referring to the accompanying drawings il- -lustrating said embodiments,

Fig. l'is a View of one form of torch, partly in section and partly in elevation, the section being taken substantially on line I-I of Fig. 2 looking in the direction of the arrows.

Fig. y2 is a sectional view through the torch taken substantially on line 2-2 of Fig. l looking in the direction of the arrows.

Fig. 3 is a sectional-view taken substantially on line 3-3 of Fig. 1 looking in the direction of the arrows.

Fig. 4 is a view similar to Fig. 1 but showing a modified form of torch, and

Fig. 5 is a sectional view taken substantially on line 5 5 of Fig. 4 looking in the direction of the arrows.

The torch comprises a fuel tank I@ which is formed of suitable material, preferably stamped metal. The tank It is of generally inverted cup shape and is provided at its lower or free edge with an outwardly bowed or flared portion II forming the base or stand on which the torch may rest. A bottom I2 for the tank eX- tends across its open and lower end and preferably is secured to the interior of the tank adjacent the inner end of the flared or bowed portion ii by welding or by any other suitable means. The bottom I2 preferably is downwardly bowed but only to such an extent as to be housed within the flared portion Il. The upper or closed end of the tank I!) is stamped so as to have one or more depressions I3 formed therein and preferably extending chordally of the upper end of the tank and on opposite sides of a cradle or trough I4 for the flame nozzle 2B .and an inclined supporting surface It for the torch valve block 23.

The cradle for the flame nozzle is stamped in the upper end of the tank I9 so as to provide a trough I4 extending partially diametrically of the tank and upwardly inclined from the center of the tank toward the circumference'thereof. The trough I4 is integrally connected to the depressions I3 by portions I5. The closed or top end of the tank I9 in line with the trough I4 is provided with an inclined supporting surface I6 that extends in a diametrical direction and is inclined downwardly from the center of the tank toward its circumference in an inclined plane parallel or substantialy parallel to the inclined plane of the bottom of the trough I4 as clearly indicated in Fig. l. The trough I4 and the inclined surface it are integrally connected by an upwardly extending portion il.

A plate I8 is located within the tank III` and extends diametrically of the tank intermediate the depressions i3 and is welded or otherwise suitably secured to the interior of the tank. The plate I8 may be'secured in position prior to the bottom l2 being secured to the tank, thus providing easy assembly. The plate IS forms with the trough I4, portions I5, inclined surface I 6 and portion Il a vaporization chamber I9 which extends the full length of the trough i4 and the surface i5.

A name nozzle 2D is mounted in the cradle or trough I4 and is permanently secured thereto by welding or other suitable means. The nozzle 2t is tubular and at its inner end is closed except for a flame opening 2|. The nozzle 2li is'provided intermediate its ends with a plurality of air vent openings 22 to provide suitable amounts of air for combustion of the vaporized fuel in the nozzle during the use of the torch. If desired, a slidable sleeve, not shown, could be positioned over the nozzle so as to be moved to expose a greater or a fewer number of the openings 22.

A valve block V23 is yrigidly secured to the inclined surface I6 by welding or other suitable means. This block is provided with a longitudinally extending bore 213 that terminates at its inner end with a. threaded counterbore 25. The bore 24 is provided with a threaded portion 26 with which cooperate the threads 21 on Ia large diameter portion of a valve `rod 28. The valve rod 28A extends through a gland packing 29 and a gland nut 30 screwed upon the externally threaded reduced nipple 3l on the outer end of the block 23. The'outer end of the rod 28 is provided .with'an operating knob 32 whereby the rod may be turned to cause it to screw inwardly and outwardly of 'the bore 24 to Aadjust the position of the 'pointed needle valve 33 formed on the reduced inner end rportion of the rod. The needle valve 33 extends into the counterbore .25 and into the bore 34 formed n 'a removable valve plug member 35 that has a reduced .externally threaded portion screwed into the counterbore 25 and an enlarged portion provided with a somewhat flared 'counterbore 36 that communicates with the bore 34 and is in alignment with Vthe opening 2I of the flame nozzle. The bore 24 in the body 23 communicates with a laterally extending passage 31 in said body and said passage in turn registers with an opening 33 in the inclined surface I6, vwherefore that portion of the bore 2li intermediate the valve V33 and the threads 21 of therod'is in communication with the vaporization chamber I9, it vbeing `noted that the rod 28 between the vthreads 21 and the Avalve 33 is of reduced diameter so as to provide a clearance between it and the wall of the bore 24. The plate I8 is provided with an opening 39 placing the interior of the tank IB in communication with the vaporization chamber TS, wherefore it willbe seen is .secured to the plate I8 and the bottom I2 by suitable means suchas by welding or the like. The interior of the lower end of the tube 40 is threaded to receive a removable filling .plug 4I which when screwed into position is lhoused within the flared portion Il of the tank. The tube 40 adjacent its .upper end is provided with openings i2 and adjacent its lower end with openings 43.

When the tank is to be filled with a suitable fuel, such as gasoline or any other thermally vaporizable fuel, itis inverted andthe filling plug lll -i's removed. The fuel may then be introduced to the tank through the tube 6 from whence it will flow through the Aopenings '42 and the openings 43 into the interior vof the tank. When a sufficient quantity vof fuel has been introduced into the tank the plug 4I is screwed into closed position and then the torch is returned to its upright position. The operator then approximately adjusts the valve 33 by turning the Iknob 32. He then places a Aquantity of lfuel in the depressions i3 and ignities such fuel 'to produce the initial heat for vaporization of the'fuel -in-the tank. The burning fuel iin thedepressions l|13 produces heat which is transmitted directly tothe interior of the 4 tank and by conduction to the name nozzle 20 and the block 23. This heat causes the fuel in the tank to vaporize whereupon the vaporized fuel flows into the chamber I9 where it is further vaporized by the heat' from the burning fuel in the depressions I3. The vaporized fuel A"then flows from the chamber I9 through the opening 38 and passage 31 into the bore 24 and past the valve 33 and into the counterbore 36, The operator now ignites the vaporized fuel passing outwardly of the counterbore 36, as will be well understood in the art to produce a flame in the nozzle 20. After the vaporized'fuel is-ignited the operator will adjust the valve 33 by the knob 32 to obtain the flame `he desires. The heat produced by the flame at the nozzle 2i! is transmitted directly to the vaporization chamber "I9 and thus `maintains Ithe maximum vaporization heat in said chamber.

vInasmuch as the Yname nozzle 20 is supported directly by the upper end ofthe tank l0, with only the vaporizatio-n chamber IS? Vand the plate 'I8lintervening :between the nozzle and the interior of the tank, it will be :seen 'that the heat from the nozzle is transmitted substantially directly Vto y'the interior of the tank to provide the maximum heat for the initial vaporiza-tion of the fuel in the tank to cause such vaporized fuel to flow into the vapo-rization chamber I9 to be finally and completely vaporized. In addition, the tube 31) will conduct heat from the plate 1S to the interior of the tank and also vthe heat-will be conducted from the nozzle 23 to the interior of 'the tank lby the portions I5 and the depressions I3 of the top of the tank. Therefore lmaximum heat for vaporization of the fuel in the tank an'd'in the chamber i9 is obtained w-itha minimum likelihoodof such heat being dissipated by radiation and the like.

In the prior art torches wherein fuel feeding -'is effected `by heat vaporization -of the fuel in the tank, the naine nozzles have been located substantial distances from the tanks and the heat from the nozzles is Ytransmitted to the tanks through relatively long conductive paths formed by tubular stems supporting the nozzles and extending into the tanks, Therefore -the arrangement .of the Aprio-r art torches provides substantial heat losses by radiation, with vthe result tha-t the desired heat for vaporization of the fuel -is no't obtained at all times, particularlywhen the torch is being used out of doors in Ycold windy weather, at which time the heat loss due to radiation is greatly increased.

lThe torch embodying the present invention is not subject to such criticism since, as pointed out, the heat from the flame nozzle is transmitted directly to the final vaporization chamber 19 'and substantially directly to the interior of the tank I `and also by lrelatively sho-rt conductive paths to the interior of the `tank through the material of the -tank and of the tube im. Therefore the torch of the present invention assures maximum heat for the initial and lthe final vapor-ization of the fuel to provide for the feeding ofthe f-uel and theproper combustion thereof. 4Consequently the eiii'ciency of the torch is greatly increased and a hotter fia-me and a minimum consumption of fuel is the result. In addition, the torch is constructed of fewer parts than theprior art torches and said parts 'require a minimum amount of machining operations .in their lproduction and are formed 1in large part by .simple stamping and welding operations.

In Figs. 4 and 5 a somewhat different form of torch embodying the invention Sis illustrated. .Insofar as this modieduformof itorch 'eo'rrespomis in construction with the previously described torch the parts are designated by the same reference characters.

The tank l in its top wall is provided with depressions corresponding to the depressions I3 of the previously described torch. It will be noted, however, that the diametral central portion 44a of the top wall 44 of the tank l!) of the modied torch projects above the remainder of the wall and is upwardly inclined from adjacent the right hand side of the torch as viewed in Fig. 4 toward the left `nand side thereof. Intermediate the depressions i3 in the wall M and in the raised portion Mia there is provided a groove 45, the bottom wall of which is curved, This groove does not extend the complete diametral width of the tank but terminates inwardly of the circumference thereof to provide raised plane supporting surfaces adjacent the periphery of the tank for a nozzle and valve casting now to be explained.

In this form of torch the ame nozzle li and the valve block il are in the form of a unitary casting. The cross sectional radius of the name nozzle and the block il is such that when the casting is superimposed from the top of the tank over the groove or trough i5 a space is provided between the casting and the wall of the groove and this space constitutes a vaporization chamber i8 extending from the opening 59 in the wall 44 to adjacent a passage in the block 4l and which passage communicates with the vaporization chamber. The casting is welded or otherwise suitably secured in position on the top of the tank. Hence it will be seen that thez vaporization chamber is provided without the necessity of utilizing any additional parts other than the flame nozzle, valve block and top wall of the tank.

The passage terminates in an upwardly facing V-portion 5| which communicates with a bore 52 formed in the block in alignment with the opening 2| of the fiarne nozzle and threaded to receive a removable plug 53 that has a passage 54 therethrough of small diameter. Th block 4l is also provided with a bore and counterbore longitudinally aligned with the passage 55 and in which the threaded portion 55 of a valve rod 56 can be screwed to adjust the tapered valvv point 51 relative to the V-portion 5! of the passage 50, as will be well understood. Suitable packing and gland nuts indicated as a whole at 58 are assembled in the countcrbore around the valve rod 56 and the latter is provided with an actuating knob 59. The block 47 is also provided with an integral extension 5i) to which a torch handle 6| can be removably connected. y

The operation of this modified form of torch is identical with the operation of the previously described form. It will be noted, however, that the modified form of torch eliminates the plate i8 of the previously described form and furthermore the flame nozzle is directly supported by the Wall 44 which also forms one wall of the vaporization chamber and hence in this modified form of torch the heat from the nozzle is directly transmitted to the chamber and to the interior of the tank to vaporize the fuel therein for combustion and feeding purposes.

Although preferred embodiments of the invention have been illustrated and described herein it will be understood that the invention is susceptible of various modifications and adaptations within the scope of the appended claims.

Having thus described my invention, I claim:

1. A blowtorch of the type specified comprising a fuel tank, a ame nozzle, a regulating valve cooperating With said nozzle, said nozzle and valve each being directly mounted on and secured to a Wall of said tank, a vaporization chamber defined in part by said wall, and means placing said chamber in communication with said valve and the interior of said tank.

2. A blowtorch of the type specified comprising a fuel tank, a flame nozzle, a regulating valve cooperating with said nozzle, a wall of said tank being formed with a depressed trough and with a supporting surface, said nozzle and valve being superimposed directly on said trough and surface respectively and secured thereto, a vaporization chamber defined in part by the trough portion of said Wall, and means placing said chamber in communication With said valve and the interior of said tank.

3. A blowtorch of the type specied comprising a fuel tank, a ame nozzle, a valve block having therein a valve cooperating with said nozzle, a wall of said tank having a diametrally extending raised portion part of which is in the form of a trough and part of which is in the form of a flat supporting surface, said nozzle and valve block being mounted respectively in said trough and on said surface and secured thereto, a plate secured interiorly of said tank beneath said trough and said surface and defining therewith a vaporization chamber, and means placing said chamber in communication with said Valve and the interior of said tank.

4. A blowtorch of the type specified comprising a fuel tank, a ame nozzle, a valve block provided with a regulating valve cooperating with said nozzle, an end Wall of said tank being provided with a central diametrally extending raised portion having a shallow trough for a portion of its length, said ilame nozzle and valve block being positioned directly on said portion and overlying said trough and of such shape as to provide a space between said nozzle and block and the bottom of said trough to create a vaporization chamber, and means placing said chamber in communication with said valve and with the interior of said tank.

5. A blowtorch of the type specified comprising a fuel tank including atop wall having on its outer side a longitudinally extending raised integral portion forming part of a vaporization chamber, said top wall adjacent said raised portion being provided exteriorly with means adapted to receive fuel for starting the torch, a flame nozzle mounted directly on said raised portion, a regulating valve operatively associated with said name nozzle and mounted on said -top wall, and means in said top wall placing said fuel tank, said vaporization chamber and said regulating valve in communication with each other.

FRITZ L. SCHWEITZER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTSy Number Name Date 1,425,362 Bingham Aug. 8, 1922 1,629,628 Kelvie May 24, 1927 1,780,152 Birnbaum Nov. 4, 1930 2,414,455 Dinklage Jan. 21, 1947 FOREIGN PATENTS Number Country Date 6,912 Great Britain of 1901 

